Varel International Announces Patent Pending PDC Cutter Testing Technologies
(CARROLLTON, Texas- 29 April 2010) - Varel International, a leading manufacturer of drill bits and global supplier to the drilling industry, announces the development and deployment of two patent pending PDC cutter testing technologies. These innovative tools measure cutter toughness and abrasion resistance to enhance and improve the development and selection of PDC cutter technology for drilling applications.
Cutter Toughness
Cutter toughness is the ability to withstand the effects of drilling dynamics. Toughness is related to the strength of the diamond-to-diamond bonding created during the High Pressure High Temperature (HPHT) sintering of the PDC cutter. Historically, test methods in the industry have been qualitative and have fallen short of providing effective data for field cutter selection.
To better measure cutter toughness, Varel has developed its patent pending Acoustical Emissions Toughness Test (AETT). AETT quantitatively assesses the strength of the diamond-to-diamond bonding. With this test a load is applied to the cutters and increased at a constant rate while an acoustic sensor detects acoustic emissions from microcracking in the diamond table. Measuring the energy released during microcracking yields a concrete assessment of the PDC toughness.
Multiple types and grades of PDC cutters can be cross compared according to their resistance to load induced microcracking yielding a highly predictive valuation of impact toughness.
Abrasion Resistance
Abrasion resistance is the cutter's ability to stay sharp as it drills. The primary drawback of traditional abrasion tests is the lack of an accurate simulated geological environment. Current tests use a homogenous rock structure which does not calibrate how moments of high impact energy affect a cutter's abrasion resistance. Varel's second patent pending test, the Bimodal Abrasive Rock Test (BART), is a laboratory abrasion resistance test which employs an engineered rock sample with highly abrasive cement cast around upright layers of high compressive strength granite to measure a cutter's abrasion resistance. The two rock samples create a load/unload cycle to simulate interbedded formations and formation transitions. By recreating this environment, BART provides a more suitable measurement of abrasion resistance correlating to field performance and yields a quantification of a specific cutter's applicability to transition drilling.
When used in combination AETT and BART testing regimens promise to significantly accelerate cutter development by speeding the qualification of new cutters and by providing more accurate quantification of prototype cutter attributes. These processes aide in the development of new cutter technology and in the selection of the best existing technology while enhancing Varel's ability to deliver drill bits with world-class performance.
About Varel International
Founded in 1947, Varel International is the world's largest independent supplier in the global oil & gas drill bit market. Headquartered in Carrollton, Texas, Varel services oil & gas, mining, and industrial markets with its comprehensive suite of roller cone and fixed cutter drill bits. The company employs more than 1,000 people and has manufacturing facilities in Carrollton, Texas; Houston, Texas; Matamoros, Mexico and Tarbes, France, as well as sales offices throughout the world. Varel's proprietary design capabilities, efficient manufacturing, and global sales force uniquely positions the company to provide high-quality drill bits that deliver excellent performance and value to its customer base. For more information, visit http://www.varelintl.com/.
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